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Basics ⬇

Basics

Overview

Benign tumor of the testicle that arises from interstitial (Leydig) cells.

Signalment

  • 33–50% of all testicular tumor in dogs but rare in cats.
  • Median age, 10 years.
  • Boxer, German shepherd, Afghan hound, Weimaraner, Shetland sheepdog, Collie, and Maltese may be at increased risk.

Signs

  • Usually incidental finding.
  • Fertility issues in breeding dogs.
  • May be associated with testosterone secretion and perianal gland hyperplasia or adenomas.
  • 4–20% of dogs will have more than 1 type of testicular tumor. Up to 50% of dogs will have bilateral tumors, only 12% of contralateral tumors will be palpable.

Causes & Risk Factors

  • Generally unknown
  • Cryptorchidism-may predispose

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

  • Sertoli cell tumor
  • Seminoma
  • Hyperadrenocorticism-with feminization
  • Hypothyroidism-with feminization

CBC/Biochemistry/Urinalysis

  • Usually normal, unless estrogen excess causes bone marrow hypoplasia (rare).
  • Various cytopenias-with estrogen excess (rare).

Other Laboratory Tests

  • High serum estradiol concentration.
  • Low serum testosterone concentration.

Imaging

  • Testicular sonography may aid in differential diagnoses.
  • Abdominal ultrasonography for retained testicles and to evaluate for concurrent malignancies.

Diagnostic Procedures

N/A

Treatment ⬆ ⬇

Treatment

Medications ⬆ ⬇

Medications

Drug(s)

  • None, unless bone marrow hypoplasia induces a dangerous cytopenia.
  • Recombinant hematopoietic colony-stimulating factors-may be useful in treating bone marrow hypoplasia.

Contraindications/Possible Interactions

N/A

Follow-Up ⬆ ⬇

Follow-Up

Patient Monitoring

None required, unless bone marrow hypoplasia

Possible Complications

Cytopenias caused by estrogen excess

Expected Course and Prognosis

Bilateral orchiectomy and scrotal ablation are often curative.

Miscellaneous ⬆

Miscellaneous

Associated Conditions

  • Prostate disease-with testicular tumor
  • Perianal gland hyperplasia/adenomas

See Also

Author Shawna L. Klahn

Consulting Editor Timothy M. Fan

Acknowledgment The author and editors acknowledge the prior contribution of Wallace B. Morrison.

Client Education Handout Available Online

Suggested Reading

Lawrence JA, Saba C. Tumors of the Male Reproductive System. In: Withrow SJ, ed., Small Animal Clinical Oncology. St Louis, MO: Elsevier Saunders, 2013, pp. 557–571.

Morrison WB. Cancers of the reproductive tract. In: Morrison WB, ed., Cancer in Dogs and Cats: Medical and Surgical Management. Jackson, WY: Teton NewMedia, 2002, pp. 555–564.